As a patient's body temperature is critical with respect to sustaining life, thermal blankets are often used to provide warmth or cooling directly to patients as needed. For instance, many post-surgery procedures include the use of a thermal blanket wherein warm air is distributed over the patient's body for body temperature control purposes for reducing the effects of shock and trauma. As such blankets may become soiled, thermal blankets are preferably of the disposable type, the blanket being formed by thermoplastic sheets heat sealable at their peripheries to define an envelope for receiving pressurized air and orifices defined in the lowermost blanket sheet permits the warm air to be directed toward the patient's body.